Power tool having noise reducing structure

ABSTRACT

A power tool includes a container having a chamber to receive a motor which has a spindle attached to a pinion and extended out of the pinion. A reduction gearing includes a housing attached to the motor and having an internal gear, two plates rotatably received in the housing and each having three rotatable gears. The pinion is engaged with the gears of one of the plates which has another pinion engaged with the gears of another plate, to allow the plates and the gears to be rotated by the motor. The pinion of the motor is extended through one of the plates, to smoothly support the plates and the gears within the housing, and to reduce shocks, vibrations, or noises that may be generated by the plates and the gears.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a power tool, and more particularly to a power tool having a structure for reducing shocks and vibrations, and thus for reducing noises, and for allowing the power tool to be smoothly driven and operated to effectively rotate or drive fasteners.

2. Description of the Prior Art

Various kinds of typical power tools have been developed and comprise a reduction gearing coupled to a motor, for being rotated or driven by the motor, to rotate fasteners.

For example, U.S. Pat. No. 6,458,058 to Fu discloses one of the typical power tools comprising a reduction gearing having three or more gears coupled to a pinion of a motor, for being rotated or driven by the motor, to rotate fasteners. Normally, the pinion of the motor is directly engaged within or between the gears, to rotate or drive the gears.

The gears are received in an internal gear disk and engaged with an internal circular teeth of the internal gear disk, for allowing the internal gear disk to be rotated or driven by the motor via the internal gear disk and the gears.

However, the internal gear disk has not been rotatably supported within a housing with any supporting devices or members, such that the internal gear disk may not be smoothly rotated within the housing, and may vibrate relative to the housing, and thus may generate great noises while working.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional power tools.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a power tool including a structure for reducing shocks and vibrations, and thus for reducing noises, and for allowing the power tool to be smoothly driven and operated to effectively rotate or drive fasteners.

In accordance with one aspect of the invention, there is provided a power tool comprising a body including a container provided thereon, the container including a chamber formed therein, a motor received in the chamber of the container, and including a spindle, a first pinion attached onto the spindle, and the spindle of the motor being extended outwardly beyond the first pinion, and a reduction gearing received in the chamber of the container, and including a housing attached to the motor and having an internal gear provided therein. The reduction gearing includes a first plate and a second plate rotatably received in the housing, three first gears rotatably attached to the first plate, and engaged with the first pinion, to allow the first gears and the first plate to be rotated by the motor, the first plate including a second pinion extended therefrom and having a bore formed therein to receive the spindle of the motor, and to smoothly support the first plate in the housing. The reduction gearing further includes three second gears rotatably attached to the second plate, and engaged with the second pinion of the first plate, to allow the second gears and the second plate to be rotated by the motor via the first plate and the first gears, and a driving device is attached to the second plate, and thus rotated by the motor via the first plate and the second plate. The first plate may be smoothly received and supported within the housing, such that the first gears and the second gears and thus the second plate may also be smoothly received and supported within the housing, such that greatly reduced shocks and vibrations or noises will be generated by the gears and the plates, and such that the power tool may be smoothly driven and operated to effectively rotate or drive fasteners.

The first plate includes three holes formed therein, and three pins attached to the holes of the first plate, and engaged in the first gears respectively, to attach the first gears to the first plate.

The second plate includes three holes formed therein, and three pins attached to the holes of the second plate, and engaged in the second gears respectively, to attach the second gears to the second plate.

The second plate includes a non-circular orifice formed therein, and the driving device includes a driving shank having a non-circular end engaged into the non-circular orifice of the second plate, to allow the driving device to be rotated in concert with the second plate. The driving device includes at least one fastener engaged with the driving shank, to secure the driving shank to the second plate.

The reduction gearing includes a panel received in the housing, and engaged with the first gears, to stably retain the first gears between the panel and the first plate. The reduction gearing includes a panel received in the housing, and engaged with the second gears, to stably retain the second gears between the panel and the second plate. The housing includes a cover secured thereto, and attached to the motor.

Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial exploded view of a power tool in accordance with the present invention;

FIG. 2 is another partial exploded view of the power tool;

FIG. 3 is a perspective view showing a housing for a reduction gearing of the power tool;

FIG. 4 is a partial cross sectional view taken along lines 4-4 of FIG. 5;

FIG. 5 is a cross sectional view taken along lines 5-5 of FIG. 4; and

FIG. 6 is a cross sectional view similar to FIG. 4, illustrating the operation of the power tool.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, and initially to FIG. 1, a power tool in accordance with the present invention comprises a body 10 formed and secured by such as two half members 11, 12, and including a container 13 formed or provided on top of a handle 14. The container 13 includes a chamber 15 formed therein for receiving a motor 20 and a reduction gearing 30 therein.

As shown in FIGS. 2 and 4-5, the motor 20 includes a spindle 21, and a pinion 22 attached or secured onto the spindle 21, so as to be rotated or driven by the motor 20. The spindle 21 of the motor 20 is extended outwardly through or of the pinion 22, and includes a free end 211 extended outwardly beyond the pinion 22, best shown in FIGS. 4 and 6.

The reduction gearing 30 includes a housing 35 having an internal gear 351 formed or provided therein (FIGS. 3, 5), and a cover 36 attached and secured to the housing 35, for securing the housing 35 to the motor 20. The cover 36 is arranged for allowing the free end 211 of the spindle 21 of the motor 20 to extend into the housing 35.

The reduction gearing 30 further includes one or more, such as two support plates 31, 32 rotatably received in the housing 35, and each having one or more, such as three holes 311, 321 formed therein to receive or to attach pins 312, 322 thereto, and a number of gears 33, 34 are rotatably engaged onto the pins 312, 322 respectively.

The pinion 22 of the motor 20 is engaged between the gears 33 (FIGS. 4-6), for allowing the gears 33 and thus the support plate 31 to be rotated or driven by the motor 20. The gears 33 are engaged or meshed with the internal gear 351 of the housing 35 (FIG. 5), to allow the gears 33 and thus the support plate 31 to be rotated or driven by the pinion 22 of the motor 20.

The support plate 31 includes another pinion 313 extended therefrom, such as extended away from the gears 33 and the motor 20, and engaged between the gears 34 (FIGS. 4, 6), for allowing the gears 34 and thus the support plate 32 to be rotated or driven by the motor 20 via the support plate 31 and the gears 33.

One or more, such as two washers or panels 37, 38 may be engaged onto the gears 33, 34 respectively, to position the gears 33, 34 to the support plates 31, 32, and to prevent the gears 33, 34 from moving or sliding along the pins 312, 322 and moving toward or away from the support plates 31, 32.

A driving device 40 includes a driving shank 41 rotatably attached or secured to the housing 35 with a gasket or bearing 42, and the driving shank 41 includes a non-circular end 43 formed thereon and extended within the housing 35, and extended into a corresponding non-circular orifice 323 of the support plate 32, and secured to the support plate 32 with one or more fasteners 44, to allow the driving shank 41 of the driving device 40 to be rotated in concert with the support plate 32, and to be effectively rotated or driven by the motor 20 via the support plates 31, 32 and the gears 33, 34.

As shown in FIGS. 2, 4, 6, the pinion 313 and the support plate 31 include a bore 314 formed therein to receive the free end 211 of the spindle 21 of the motor 20, and thus to allow the pinion 313 and the support plate 31 to be stably attached onto the spindle 21 of the motor 20, and thus to allow the pinion 313 and the support plate 31 to be smoothly received and supported within the housing 35.

It is to be noted that the support plates 31, 32 and the gears 33, 34, and thus the driving shank 41 of the driving device 40 will be rotated or driven by the motor 20 in great rotational speeds. The smoothly receiving of the support plates 31, 32 and the gears 33, 34 within the housing 35 by the spindle 21 of the motor 20 may prevent the support plates 31, 32 and the gears 33, 34 from being vibrated relative to the housing 35, and thus may reduce noises that may be generated when the support plates 31, 32 and the gears 33, 34 are rotated relative to the housing 35.

Accordingly, the power tool in accordance with the present invention includes a structure for reducing shocks and vibrations, and thus for reducing noises, and for allowing the power tool to be smoothly driven and operated to effectively rotate or drive fasteners.

Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed. 

1. A power tool comprising: a body including a container provided thereon, said container including a chamber formed therein, a motor received in said chamber of said container, and including a spindle, a first pinion attached onto said spindle, and said spindle of said motor being extended outwardly beyond said first pinion, a reduction gearing received in said chamber of said container, and including a housing attached to said motor and having an internal gear provided therein, said reduction gearing including a first plate and a second plate rotatably received in said housing, three first gears rotatably attached to said first plate, and engaged with said first pinion, to allow said first gears and said first plate to be rotated by said motor, said first plate including a second pinion extended therefrom and having a bore formed therein to receive said spindle of said motor, and to smoothly support said first plate in said housing, said reduction gearing further including three second gears rotatably attached to said second plate, and engaged with said second pinion of said first plate, to allow said second gears and said second plate to be rotated by said motor via said first plate and said first gears, and a driving device attached to said second plate, and thus rotated by said motor via said first plate and said second plate.
 2. The power tool as claimed in claim 1, wherein said first plate includes three holes formed therein, and three pins attached to said holes of said first plate, and engaged in said first gears respectively, to attach said first gears to said first plate.
 3. The power tool as claimed in claim 1, wherein said second plate includes three holes formed therein, and three pins attached to said holes of said second plate, and engaged in said second gears respectively, to attach said second gears to said second plate.
 4. The power tool as claimed in claim 1, wherein said second plate includes a non-circular orifice formed therein, and said driving device includes a driving shank having a non-circular end engaged into said non-circular orifice of said second plate, to allow said driving device to be rotated in concert with said second plate.
 5. The power tool as claimed in claim 4, wherein said driving device includes at least one fastener engaged with said driving shank, to secure said driving shank to said second plate.
 6. The power tool as claimed in claim 1, wherein said reduction gearing includes a panel received in said housing, and engaged with said first gears, to stably retain said first gears between said panel and said first plate.
 7. The power tool as claimed in claim 1, wherein said reduction gearing includes a panel received in said housing, and engaged with said second gears, to stably retain said second gears between said panel and said second plate.
 8. The power tool as claimed in claim 1, wherein said housing includes a cover secured thereto, and attached to said motor. 